Typical imaging devices, such as printers and copiers, use a page description language (e.g., Postscript) to print documents. Prior to printing, a language interpreter classifies the objects in a document or page into a finite set of categories such as text, graphics, or image. Because each of these categories of objects has different visual characteristics, it is often desirable to render the objects using different types of halftone screens. For example, text objects may be rendered using a higher frequency halftone screen than that used for printing graphics or image objects to improve the edge definition of the text characters. However, higher frequency halftone screens magnify undesirable printer artifacts, such as “banding” and “noise,” which become visually more noticeable as the text characters being printed get larger (i.e., the font size increases).
To prevent unwanted print artifacts in large text, many printers change the halftone frequency of the halftone screen for text when the font size exceeds a predetermined threshold. This threshold value is predetermined, and is set in the RIP code at the time of manufacture. For text characters printed at or below the threshold, high frequency halftone screens are used to print the characters, while the normal frequency halftone screen is used to print characters that are above the threshold. However, the predetermined threshold value is fixed for all users, and can only be changed via a special file that must be acquired from the manufacturer and downloaded to the imaging apparatus. This special file is typically not readily available to the public. Thus, there is no user-friendly way for a given user to modify or adjust the threshold value to tailor the threshold value to a given circumstance.